A catalyst will change or influence or effect three major parameters which are:

A catalyst will change or influence or effect three major parameters which are:
 http://dramarnathgiri.blogspot.in/2013/03/reforming-catalyst-technology.html

1. Rate of a reaction
2. Energy required for a chemical reaction
3. Sequence of mechanism steps of a chemical reaction
But it does not change the Equilibrium of the reaction
Some of the images of the catalysts which are used for some specific reactions, these catalysts selection depend on the shape, activity; surface area etc, bulk production of chemical will depend on the choice of catalysts.

Iron Catalyst

Iron based catalyst which is mostly used for ammonia synthesis reaction of Nitrogen and Hydrogen reactants, its optimum dimensions are about 1.5 to 3 mm diameter and have lifetime form 5 to 10 years